Oscillation criteria for odd higher order nonlinear neutral differential equations with positive and negative coefficients

摘要

In this paper, the authors study oscillatory and asymptotic behavior of solutions of a class of nonlinear higher order neutral differential equations with positive and negative coeffi- cients of the form (a(t)(b(t)(y(t)+p(t)y( σ (t))) ) ) (n.2) + q(t)G(y( α (t))). h(t)H (y( β (t))) = 0(E) for n 3, n is an odd integer, 0 p(t) p 1 < 1and.1 < p 2 p(t) 0. The results in this paper generalize the results of Panigrahi and Basu [ 9 ] and various results in the literature. We establish new conditions which guarantees that every solutions of (E) either oscillatory or converges to zero. Examples are considered to illustrate the main results.